1# SPDX-License-Identifier: GPL-2.0 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/iio/proximity/devantech-srf04.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: Devantech SRF04 and Maxbotix mb1000 ultrasonic range finder 8 9maintainers: 10 - Andreas Klinger <ak@it-klinger.de> 11 12description: | 13 Bit-banging driver using two GPIOs: 14 - trigger-gpio is raised by the driver to start sending out an ultrasonic 15 burst 16 - echo-gpio is held high by the sensor after sending ultrasonic burst 17 until it is received once again 18 19 Specifications about the devices can be found at: 20 https://www.robot-electronics.co.uk/htm/srf04tech.htm 21 22 https://www.maxbotix.com/documents/LV-MaxSonar-EZ_Datasheet.pdf 23 24properties: 25 compatible: 26 enum: 27 - devantech,srf04 28 - maxbotix,mb1000 29 - maxbotix,mb1010 30 - maxbotix,mb1020 31 - maxbotix,mb1030 32 - maxbotix,mb1040 33 34 trig-gpios: 35 description: 36 Definition of the GPIO for the triggering (output) 37 This GPIO is set for about 10 us by the driver to tell the device it 38 should initiate the measurement cycle. 39 See Documentation/devicetree/bindings/gpio/gpio.txt for information 40 on how to specify a consumer gpio. 41 maxItems: 1 42 43 echo-gpios: 44 description: 45 Definition of the GPIO for the echo (input) 46 This GPIO is set by the device as soon as an ultrasonic burst is sent 47 out and reset when the first echo is received. 48 Thus this GPIO is set while the ultrasonic waves are doing one round 49 trip. 50 It needs to be an GPIO which is able to deliver an interrupt because 51 the time between two interrupts is measured in the driver. 52 maxItems: 1 53 54 power-gpios: 55 description: 56 Definition of the GPIO for power management of connected peripheral 57 (output). 58 This GPIO can be used by the external hardware for power management. 59 When the device gets suspended it's switched off and when it resumes 60 it's switched on again. After some period of inactivity the driver 61 get suspended automatically (autosuspend feature). 62 maxItems: 1 63 64 startup-time-ms: 65 description: 66 This is the startup time the device needs after a resume to be up and 67 running. 68 minimum: 0 69 maximum: 1000 70 default: 100 71 72required: 73 - compatible 74 - trig-gpios 75 - echo-gpios 76 77additionalProperties: false 78 79examples: 80 - | 81 #include <dt-bindings/gpio/gpio.h> 82 proximity { 83 compatible = "devantech,srf04"; 84 trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>; 85 echo-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>; 86 }; 87